Electroretinogram and visual field changes in a case of birdshot chorioretinopathy

This case report explores the role of the visual field perimetry and electroretinogram (ERG) in cases of non-infectious uveitis in the assessment and monitoring of retinal function and response to treatment. A 59-year-old Caucasian female presenting with bilateral posterior uveitis newly diagnosed as birdshot chorioretinopathy (BSCR) presenting with bilateral decrease in visual acuity and cystoid macular edema, as well as a paracentral scotoma in the right eye. The diagnosis and follow-up of the case was done using visual field perimetry, optical coherence tomography (OCT), and ERG. Baseline ERG showed a marked decrease in the amplitudes of the scotopic and photopic responses and a delay of peak times mainly in the right eye. Mycophenolate mofetil at 2 g/day and oral prednisolone at 1 g/kg/day were administered with gradual tapering of the corticosteroids. After 5 months, there was a noticeable improvement in the visual acuity, macular edema in OCT, and an obvious increase in the amplitudes of the ERG associated with a decrease in peak times, particularly in the 30 Hz photopic 3.0 Flicker of the right eye. This case report highlights the importance of the peak time and wave amplitudes of the 30 Hz photopic DA 3.0 Flicker as being a sensitive parameter in the diagnosis and follow-up of BSCR.